1. Field of the Invention
The present invention relates to a cost estimation method and system, and computer readable medium for the cost estimation method. In addition, the present invention also relates to a part cost estimation method and system for estimating the cost of a part which is prepared by, for example, cutting or turning a source material.
2. Discussion of the Background
Manufacturers perform their business while having dealings with many suppliers. Conventionally, suppliers have been determined for such a reason that the suppliers are the affiliate companies of the manufacturers; or the manufacturers have dealt with the suppliers for a long period of time. However, such a business system cannot be used in the current price competition age.
In addition, a business method in which a company offering a minimum price is chosen as the supplier for a manufacturer is also adopted. However, it is difficult for the manufacturer to maintain a good relationship with such a company for a long period of time.
On the other hand, members of each factory and office of a manufacturer try to discover problems to be solved, and continuously perform improving activities therefor. However, it is difficult for the members to perform the improving activities while objectively evaluating the business system of the factory and office of the manufacturer.
Therefore, there are often the cases in which wasteful activities such that energy is consumed for unimportant problems (i.e., energy is not consumed for important problems), are performed.
In addition, estimation of the costs of parts to be prepared for a product to be manufactured needs knowledge concerning manufacturing processes of the parts and facilities used for manufacturing the parts.
Currently, computer-aided part cost estimation methods have been developed and introduced, and thereby persons who are not familiar with a part and processings to be performed on the part can estimate the cost of the part.
For example, Japanese Laid-Open Patent Publication No. 07-282142 discloses a cost estimation method in which cost estimation processes of from a process in which processing factors are extracted to a process in which the cost is estimated are automatically performed. This cost estimation method includes the following steps:    (1) the shape of a metal plate product, cost of which is to be estimated, is recognized using drawing information thereof (i.e., using preliminarily prepared cross-sectional shape data);    (2) a process suitable for producing the metal plate product is selected;    (3) the cost of the metal plate product is estimated based on the process information.
However, this cost estimation method can be used only for metal products made by using a die. Therefore this method cannot be applied to the parts which are made by, for example, cutting a rod material to form small rods; chamfering the small rods; grooving the small rods; radially drilling the small rods; edge-dressing; and fraise processing. Namely, the cost estimation method cannot be applied to the parts which are manufactured by subjecting a material to various cutting processings.
In addition, the cost estimation method have drawbacks in that a theoretical cost estimation cannot be performed and the cost estimation is rough.
Further, in the cost estimation method the cost of parts cannot be estimated for each of the facilities which can be used for producing the parts. Therefore, the cost estimation method has a drawback in that it is impossible to select the most suitable facility by which parts having good qualities can be produced at a minimum cost.
Furthermore, the cost estimation method has a drawback in that cost information of other section members cannot be used therefor.
Because of these reasons, needs exist for a cost estimation method and system which can be used when advantages and disadvantages of a business are grasped; and a parts cost estimation method and system by which a pats cost can be easily precisely estimated.